Published on February 20, 2008
This pronouncement was made by Prince Mahidol in a speech to medical students more than eight decades ago. The guiding advice was also enshrined as part of the philosophy of Mahidol University.
Our mission covers not only medical care, but teaching, training and research in the quest for innovations. There's no doubt clinical research has a great impact on the development of medical care. Yet often, research studies never give rise to an appropriate therapy or medicine. Indeed, for a majority of the findings in basic and molecular research there is no beneficial outcome for the community. But if it weren't for the curiosity and enthusiasm of scientists - some of them taking years or even their whole lives to discover one valuable thing - there would be no progress.
Targeted therapy in breast cancer is one of the best examples of a new treatment derived from a great effort of a group of scientists. They were led by Professor Axel Ullrich, who received the prestigious Prince Mahidol Award for medicine in 2007.
Ullrich is an internationally renowned molecular geneticist and director of the Department of Molecular Biology at the Max Planck Institute of Biochemistry. For more than 25 years, he has been a leader in gene technology, translating basic scientific discoveries into medical applications that can save peoples' lives.
Today, most anti-cancer drugs don't just kill cancer cells. They also attack the rapidly dividing cells from which cancer cells come. As a consequence, other normally rapidly dividing cells in the body such as white blood cells, hair cells, mucosal cells of the alimentary tract etc, are in the firing line as well, which causes major side effects sometimes leading to death.
What is targeted therapy? Basically it is a type of medication which blocks the growth of cancer cells by interfering with specifically targeted molecules called oncogenes, which contain the genetic material that carries the ability to induce cancer. The medication targets only those cells with oncogene codes or receptors, causing less harm to normal cells.
The effective agents of targeted therapy's medication are small molecules and monoclonal antibodies. There are hundreds of these currently under investigation but so far only a few have been found to be effective, and approved by the FDA. Herceptin, or Trastuzumab, is one of those.
Ullrich discovered and evaluated the biological and clinical significance of a breast cancer oncogene called HER2 or human epidermal growth factor receptor. He found that breast cancer with HER2 over-expression is associated with an aggressive character, rapid spread and reduced survival rates. His laboratory then discovered several monoclonal antibodies against HER2, one of which was subsequently developed into Herceptin (Trastuzumab), as a weapon specifically against those aggressive cancers showing positive for HER2.
There's now evidence that Trastuzumab taken in combination with other anti-cancer drugs increases response rates, depresses cancer progress and ups survival ratesamong breast cancer patients.
However, the results are not uniform in all patients, and some take longer to respond. A clearer understanding of the mechanisms that contribute to Trastuzumab resistance is needed to increase the magnitude and duration of response.
A prototype of targeted therapy, Trastuzumab has become a model for other drugs to cope with other types of cancers, such as Bevacizumab (Avastin) for colon cancer, Rituximab for lymphoma and Imatinib mesylate for gastrointestinal stromal tumours.
In the near future, targeted cancer therapy will give doctors better ways to tailor treatment based on the unique set of molecular targets produced by a patient's tumour. The treatment will be more selective, damaging fewer normal cells, reducing side effects and improving quality of life.
However, as these technologies are foreign-based, the cost of treatment will undoubtedly be very expensive. Thailand's budget for cancer treatment will eventually be inadequate. Our healthcare technology will become foreign-dependent if no serious action focusing on our own research and development is taken.
By supakorn rojanin, md Deputy dean of public relations and special affairs, Siriraj Hospital's Faculty of Medicine